Medical Alert Key Chain Charm, "Blood thinner", Stainless Steel. (Includes FREE Engraving) blood thinner medical alert, Heavy duty stainless steel construction, will not rust or tarnish, safe for water. Deep stamped custom inscribing. very easy to read will not scratch off or wear out heavy duty key chain Customizable! 3 lines with 16 characters per line, stamped on the back. Made in and ships from U.S.A